Increasing attacks on social activists have spurred several non-governmental organisations to unite and demand protection from police.In the most recent attacks, 70-year-old activist H. Da Lima was brutally attacked with a sickle on March 5 when he protested against noise pollution in a silence zone in Andheri. Another activist James John was threatened when he objected to the cutting down of a tree without the permission of the civic body.Da Lima has been constantly fighting against encroachments, illegal construction and noise pollution and was effective in curbing illegal activities.But this time there was an attempt to silence him, activists say. "He had complained of the use of loudspeakers at a Muharram function going late into the night," his lawyer Raju Moray said at a press conference yesterday."People in the locality did not say anything because of fear. He had filed a First Information Report on March 2 stating that his life was in danger and three days later he was attacked. So far no arrests have been made."In another incident, an AGNI (Action for Good Governance and Networking in India) activist was threatened by Subhash Sawant, former civic corporator of Shiv Sena, when he asked questions about why a tree's branches were cut without prior permission from the civic body. "Most of the time activists are working singlehanded and thus become vulnerable to threats from local ruffians or organised mafia," said Sumaira Abdulali, Convenor of Mitra (Movement against Intimidation, Threats and Revenge against Activists).Violence is often used to instill fear and intimidate the local populace and this encourages the anti-social elements to carry out their activities brazenly, she said.The worst incident was that of the murder of Navleen Kumar who was killed in Nalla Sopara by the land mafia. Abdulali herself was attacked at Kihim near Alibag when she confronted the sand mafia whilst Suryakant Panchal was attacked at Mahabaleshwar a few months back.Though the activists held a Solidarity Meet last year, Mitra will keep a record of the activities of activists from various areas and identify threatening or violent situations. The NGOs plan to meet Maharashtra Home Minister R. R. Patil and demand action against the culprits.